Causes

Tapeworm infection in people usually results from eating undercooked foods from infected animals. Pigs or cattle, for example, become infected when grazing in pastures or drinking contaminated water. People can also become infected by eating contaminated fish that is raw or undercooked.

The parasites mature in the animal’s intestines to pea-shaped larvae. They spread to the animal's blood and muscles. They are then transmitted to people who eat the contaminated food. This method is more common with beef or fish.

Tapeworms can also be passed by hand-to-mouth contact if you touch a surface contaminated with tapeworm eggs and then touch your mouth. This method is more common with pork.

Risk Factors

The following factors may increase your chance of a tapeworm infection:

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Centers for Disease Control and Prevention. Traveler's Health—Yellow Book: Taeniasis. Centers for Disease Control and Prevention website. Available at:
http://wwwnc.cdc.gov/travel/yellowbook/2014/chapter-3-infectious-diseases-related-to-travel/taeniasis. Updated July 10, 2015. Accessed February 23, 2016.